Method getFirstAttributeOffset

src/jvm/clojure/asm/ClassReader.java:3184–3222

@return the offset in #b of the first ClassFile's 'attributes' array field entry.

()

  /** @return the offset in {@link #b} of the first ClassFile's 'attributes' array field entry. */
  final int getFirstAttributeOffset() {
    // Skip the access_flags, this_class, super_class, and interfaces_count fields (using 2 bytes
    // each), as well as the interfaces array field (2 bytes per interface).
    int currentOffset = header + 8 + readUnsignedShort(header + 6) * 2;

    // Read the fields_count field.
    int fieldsCount = readUnsignedShort(currentOffset);
    currentOffset += 2;
    // Skip the 'fields' array field.
    while (fieldsCount-- > 0) {
      // Invariant: currentOffset is the offset of a field_info structure.
      // Skip the access_flags, name_index and descriptor_index fields (2 bytes each), and read the
      // attributes_count field.
      int attributesCount = readUnsignedShort(currentOffset + 6);
      currentOffset += 8;
      // Skip the 'attributes' array field.
      while (attributesCount-- > 0) {
        // Invariant: currentOffset is the offset of an attribute_info structure.
        // Read the attribute_length field (2 bytes after the start of the attribute_info) and skip
        // this many bytes, plus 6 for the attribute_name_index and attribute_length fields
        // (yielding the total size of the attribute_info structure).
        currentOffset += 6 + readInt(currentOffset + 2);
      }
    }

    // Skip the methods_count and 'methods' fields, using the same method as above.
    int methodsCount = readUnsignedShort(currentOffset);
    currentOffset += 2;
    while (methodsCount-- > 0) {
      int attributesCount = readUnsignedShort(currentOffset + 6);
      currentOffset += 8;
      while (attributesCount-- > 0) {
        currentOffset += 6 + readInt(currentOffset + 2);
      }
    }

    // Skip the ClassFile's attributes_count field.
    return currentOffset + 2;
  }

  /**
   * Reads a non standard JVMS 'attribute' structure in {@link #b}.